2015 BMW M4 Convertible: Heavy Metal

What price toplessness? Weight, for starters.

Update 4/18/14: BMW has announced that pricing for the 2015 M4 convertible will start at $73,425. That represents an increase of $8300 compared with the 2015 M4 coupe and $1750 versus the 2013 M3 convertible. Additional pricing information will be available closer to the car’s on-sale date; the M4 convertible will arrive in U.S. dealerships later this summer.

Purists never warmed to the previous-gen BMW M3 convertible and its porky folding hardtop, but the marketplace accepted it just fine. So, tacking on a similar roof structure to the M4—the moniker for all two-door M3s under BMW’s new nomenclature strategy—was a no-brainer. The latest addition to the 4-series lineup appears to have been designed especially for life on the boulevard, where onlookers’ attention will be captured by the droptop’s sultry lines and held by the aggressive bellow emanating from the M4’s four polished exhaust pipes.

Let’s get the bad news out of the way: This is a heavy car. Even though BMW was able to shave some 90 pounds from its V-8–powered predecessor, the M4 convertible still tips the scales at a claimed 4055 pounds. That's 525 pounds more than an M4 coupe, and the sole blame for this lies with the hardtop, which is essentially carried over from the old M3 ’vert and wasn’t subjected to any weight-saving measures.

MICHAEL SIMARI, THE MANUFACTURER

All other changes to the M3 and M4, such as structural optimization, lightweight seats, and carbon-fiber components, are applied to the convertible, too. The heavier weight results in a performance loss, which is reflected in the zero-to-60 times: BMW says that the variable-roof M4 needs 4.4 seconds to reach 60 when equipped with a row-your-own six-speed and 4.2 with the seven-speed dual-clutch automatic. Regardless of gearbox, the convertible is 0.3 second slower to 60 than its fixed-roof counterpart. Top speed, however, is governed at the same 155 mph—a velocity the convertible should reach with remarkable ease.

We suspect convertible shoppers will miss the old V-8 more so than coupe buyers, as occupants could mainline its sinister rumble with the top down. Nonetheless, the new straight-six is as quintessentially M as it gets these days. Despite being aided by a pair of turbos, the 3.0-liter S55 engine—a distant relative of the 435i's N55—races up to a 7600-rpm redline. It’s rated at 425 horsepower (available at 7300 rpm) and 406 lb-ft of torque (available from 1850 rpm).

The M4 convertible comes with an electronically controlled rear differential. In M Dynamic mode, this setup allows for some wheelslip while keeping its pilot from impending doom—making hero maneuvering relatively easy. For those genuine heroes among us, the stability-control system can be turned off altogether. The droptop M4 gets the same electrically assisted power-steering system as do its fixed-roof two- and four-door siblings, and the setup is exclusive to the M variants of the 3- and 4-series.

MICHAEL SIMARI, THE MANUFACTURER

The M4 convertible looks the part inside and out: It gets M-specific front and rear fascias, bespoke aluminum wheels, and an abundance of requisite “M” badging. There’s no word yet on pricing, but the delta between coupe and convertible 435i is nearly $9000. Considering the closed-roof M4 starts at $65,125, logic dictates the open-top M4 won’t cost much less than $75K.

The 2015 BMW M4 convertible concludes the proliferation of the Bavarians’ M3 and M4 models: there will be no M3 Sport Wagon, no M3 Gran Turismo, and no M4 Gran Coupe. Purists might prefer the M4 coupe or the four-door M3, but the M4 convertible is sure to settle in comfortably on the placid parkways that the old M3 convertible called home.